The present invention relates to an apparatus for mixing and dispensing two substances.
More particularly, the present invention relates to an apparatus for mixing, when required for use, a liquid solvent with either a solid or liquid substance to be dissolved in the solvent, storing the solution thus obtained and dispensing dosed amounts of the solution, under sterile conditions.
The present invention specifically tackles the problem of extemporaneously preparing and dispensing dosed amounts of pharmaceutical preparations which result from the extemporaneous mixing of a liquid solvent, which is kept in a first container, with a pharmaceutical substance or drug in powder or liquid form, kept in a second container, the pharmaceutical substance being mixed with or dissolved in the solvent when required for use.
It is known that difficulties are often encountered when a liquid (e.g. a solvent) kept in a first sealed container is to be transferred under aseptical conditions into a second container which is also sealed, wherein a substance in solid or liquid form is placed. This situation occurs particularly in the pharmaceutical art wherein solutions, suitable for intravenous or oral administration are often extemporaneously prepared directly by the user by mixing a liquid solvent with a liquid or solid pharmacologically active agent, both the solvent and the active agent being stored separately in distinct containers up to the moment of mixture preparation.
Several devices have been disclosed, which are provided with pumping means for carrying out the transfer of a liquid solvent from a first sealed container into a second sealed container under aseptical conditions. These devices are costly and cumbersome and frequently do not afford satisfactory results.
It has been also proposed to keep one of the containers under vacuum, so that the vacuum causes, when the containers are connected to each other by means of a double-tipped, hollow needle inserted through the rubber plugs of both containers placed in superimposed relationship, the passage of the liquid solvent to occur from the container at atmospheric pressure into the container under vacuum. Also these arrangements have proved to be costly and cumbersome.
More recently, in order to overcome the foregoing drawbacks, in the U.S. patent application Ser. No. 045,165 filed June 4, 1979, now U.S. Pat. No. 4,244,467, in the name of the same assignee as this application, an apparatus for mixing and dispensing two substances has been disclosed which comprises, in combination, a first container, a second container, a plug seated in the neck of the second container and having a recess which is open in the upward and outward direction, and an elongated transfer spout secured in the base of the recess and projecting both inwardly into and outwardly from the second container. The spout is provided with two substantially parallel passages extending therethrough. The passage openings are located at different heights by the provision of bevelled end surfaces on the transfer spout.